480GB is the new 240GB: Crucial’s M500 SSD reviewed

SSDs are cheaper than ever. How does the latest generation stack up?

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Remember Intel's old X25-M SSD? The drive came out in 2008 and played a big role in seeding a solid-state storage revolution that continues to sweep across the PC industry. SSDs have come a long way since those early days, when the X25-M 80GB was considered a relative bargain at $600. That worked out to seven dollars per gigabyte, a far cry from the sub-$1 prices that have democratized the technology in recent years.

There is perhaps no better illustration of how far we've come than Crucial's new M500 SSD. For the same $600 asking price as the old X25-M, one variant of the M500 delivers a staggering 960GB of storage. Do the math, and you're looking at 63 cents per gig—an order of magnitude reduction in cost. How's that for progress?

Fittingly, these lower prices have been driven in part by cooperation between Intel and Micron, Crucial's parent company, who collaborate on NAND production through a joint venture dubbed IM Flash Technologies. IMFT fabbed the 50-nm flash chips for the X25-M, and it has since moved to finer process tech at 35, 25, and now 20 nanometers. Each new process packs more gigabytes per wafer, increasing bit densities and decreasing prices.

While the M500 960GB represents a sort of pinnacle for SSD progression, its $600 price tag is still rather steep. The 240 and 480GB versions are more affordable, and those are the ones we've gathered to review today. As you'll see, there's much more to the M500 than its peak capacity.

Meet the new flash

As you've probably deduced already, the M500's MLC memory chips are built on a 20-nm manufacturing process. There's a difference between this NAND and what's lurking inside Intel's 20-nm 335 Series, though. The memory chips in the Intel and most other contemporary SSDs weigh in at 64Gb (8GB) each, while the M500's NAND chips have twice that capacity.

This is the first drive we've seen with 128Gb NAND, and the shift has interesting implications. For one, it makes hitting higher capacities possible with fewer dies, which is probably part of the reason the 960GB drive costs much less than its terabyte-class peers. Having fewer dies isn't always better, though. SSD controllers rely on parallelism for maximum performance; past a certain point, drives with fewer NAND dies are actually slower.

With most SSDs, performance starts to fall off at capacities below 240-256GB, suggesting that current controllers favor 32-die configurations. That makes sense, since most controllers have eight channels and can address four chips per channel. The M500 240GB uses only 16 flash dies, and its performance specifications reveal that configuration isn't ideal.

To see the M500's full performance potential, you'll need at least the 480GB version. The 240GB model has a much slower sequential write speed rating, and its random I/O rates are lower, as well. The 120GB drive is slower still, with only one NAND die for each of the controller's eight channels. No wonder Crucial is skipping a 60GB variant.

There's no difference in the performance ratings attached to the 480 and 960GB models, though. Also, note how the per-gigabyte price goes up as the drive capacity drops. Somewhat surprisingly, the 960GB drive delivers the best value of the bunch; it's the only one that dips close to 60 cents per gig. The prices for the other models are nothing special.

Beneath its grey metal exterior, the M500 is anchored by a Marvell 88SS9187 controller chip. This is an eight-channel design with—you guessed it—four chip-enables per channel. The controller combines a dual-core CPU with a 6Gbps SATA interface and support for DDR3 cache memory. It also has a built-in RAID engine and hardware support for 256-bit AES encryption.

The RAID engine works in conjunction with RAIN, a flash redundancy scheme that's also employed by Micron's enterprise-grade SSDs. This mechanism reserves a portion of the flash for parity data, which is why the M500 series has somewhat lower capacities, similar to those of SandForce-based drives.

Crucial also takes advantage of the Marvell controller's encryption hardware. The M500 supports the TCG Opal 2.0 and IEEE 1667 standards, making it compatible with the BitLocker encryption built into Windows 8. This is the first SSD we've seen with explicit support for Win8's encryption tech.

In addition to protecting bits and bytes from prying eyes, the M500 guards against data loss due to unexpected power failures. See all the little capacitors in the bottom right corner of the circuit board pictured above? Those store enough power to allow the M500 to shut down gracefully if the lights go out or your battery dies.

Speaking of mobile applications, the M500 comes in a slim 7-mm form factor compatible with thinner notebooks. The drive still has the standard mounting holes used by all 2.5" notebook drives, and Crucial includes an adhesive-backed spacer to ensure a tight fit in 9.5-mm notebook bays. Versions of the M500 with even smaller mSATA and NGFF M.2 form factors are also in the works, although they'll be limited to 480GB and smaller capacities.

To deal with cramped notebook internals that have little airflow, the M500 employs an adaptive thermal management system. If the drive temperature exceeds 70°C, "NAND operations" are reduced by "approximately 40 percent" until thermals return to normal. This throttling doesn't affect the speed of the SATA link, but it will lower overall drive performance.

Like most consumer-grade SSDs, the M500 is covered by a three-year warranty. Crucial says the drive can withstand 40GB of writes per day for five years, which works out to 72 terabytes—plenty for even relatively heavy use. It's worth noting that this endurance specification is considerably more optimistic than the one slapped on Intel's 335 Series SSD. That 20-nm drive is only rated for 20GB per day for three years, or 22TB in total.

The effects of cell degradation and interference are more pronounced on NAND chips built with finer fabrication processes, so the M500's generous endurance rating is certainly comforting. Unfortunately, there doesn't appear to be any way to monitor flash wear or how many bytes have been written to the drive. Unlike rivals Intel and Samsung, Crucial doesn't provide utility software with a built-in health indicator. The M500's payload of SMART attributes doesn't contain any references to flash wear or bytes written, either. Several of the SMART attributes are labeled "Vendor-specific," but you'll need to guess what they track and read the associated values using third-party software.

Without accompanying software, the M500's overall package feels especially spartan. It doesn't help that the drive is shipped without the 3.5" bay adapter commonly included with 2.5" SSDs. That plastic spacer is the only other thing in the box.

58 Reader Comments

It's not a matter of intentionally crippling. The drive's performance depends on the controller being able to do things to lots of different NAND chips at once. The 240GB has fewer physical NAND chips, and so the controller can only do what it can do. Add more chips and the controller can do more things at the same time and the drive gets faster.

Buying an SSD for me has so far always been a matter of compromise, because they've never been big enough. A 960GB SSD is right at the bottom end of what I'd consider desirable for my desktops and laptops, so this is great news. I'll be buying several of these over the next year or so. Splitting work between a small SSD for boot & apps and a larger HDD for docs & media is a pain in the ass--I'd rather just throw a bit more money at the problem and keep everything on one drive.

With the advent of libraries in Windows 7/8 I have barely noticed my documents being off loaded to a different drive. Not to mention I run RAID on my secondary drives that I don't want on my main SSD.After the initial setup of organizing I really see zero different between "My Documents" going to a folder on my C drive or my Z drive.It is a minor nuisance I can put up with to handle the HUGE price discrepancy(Considering I have 4TB of storage on my home machine).

Crucial let me down in two ways. First, I've not had the problem with SSD's where you had to unplug them once a month in order for their internal software to reorganize. Without doing that, the drive freezes and will not operate. Can you imagine if you had to take the transmission off your car once a month and run the engine overnight so the engine would function?

Secondly, their after warranty support IS NON-EXISTANT. If you have a problem with your drive after warranty wears out, they want NOTHING to do with you. They won't service it, repair it, exchange it for a fee.... TOTALLY THE WORST CUSTOMER CARE I'VE EVER HAD.

So, beware of Crucial. I've had much better performance and service with the other manufacturers.

I admire you guys wanting to go full SSD and ditch the old HDDs, but I don't have that kind of $ for my build to be throwing around upgrades as upgrading my GPU/CPU is always the top priority (can't wait till the 8000 series of Radeon GPUs come out so I can get a 7990 on the cheap)

I'm perfectly happy with my Samsung 840 120GB (I only paid $80 for it and it came with a $20 rebate!) on my aging Intel X58 mobo (only has SATA II support) even with my crappy BIOS that never gets upgraded anymore still gets a 28 second cold boot

Sure, you may be able to buy 18 TB of 3.5" drive storage for 600$, but the M500 marks another important milestone for SSDs: laptop drive capacity. The biggest 9 mm height, 2.5" HDD that you can buy is 1 TB, practically the same as the 960 GB capacity of the biggest M500. Now the choice between SSD and HDD for a laptop becomes just a question of budget, not capacity.

I'm confused about the reference to file compressibility in the Win7 xcopy benchmark section on page 5. This Crucial SSD uses a Marvel controller, not Sandforce, so file compressibility doesn't enter into it.

Secondly, their after warranty support IS NON-EXISTANT. If you have a problem with your drive after warranty wears out, they want NOTHING to do with you. They won't service it, repair it, exchange it for a fee.... TOTALLY THE WORST CUSTOMER CARE I'VE EVER HAD.

Huh?

Name a drive manufacturer who services/repairs/exchanges a failed drive once it's out of warranty.

Drives are consumable items. Once they stop working, as they all do sooner of later, they're paperweights.

In which case they're a three-bit-per-cell design (with lots of really clever calibration at quite fine granularity to keep the eight levels well apart), which I think explains the relatively slow write speeds and the really awful durability (40GB of writes per day, when the drive can write 400MB per second; you can use up its lifetime permitted writes in five hours).

I have SSDs for boot drives. But I have a camera that spits out 36 megapixel images. A 4TB Thunberbolt drive is screaming fast. Way faster than half the speed of the 240gig drive in this review. For the money, I'm stuck with platters for my main storage. But with Adobe allowing Photoshop Lightroom 5 to work on proxies while the big files stay at home, and it populates my edits when the big drive is hooked up again, I can be very happy with a MacBook Pro and a 512 gig drive, and a small bus-powered Thunderbolt or USB 3 drive for temporary storage of new images when I'm in the field.

Things are getting better and faster, but you have to go with being reasonable too.

I see no reason for why Crucial should hold longer than the Samsung. This review is pure win for Samsung, being faster and cheaper.

Yeah I've been thinking about buying a ~500GB Samsung 840 drive for a while. This is slower than the Pro and the normal 840 is about $50 cheaper for a slight hit to write speed. For gaming and normal day to day I can't see the paying more for either the Crucial or the Pro.

Have to agree, the 840 seems to come up smelling roses here for performance/price. Seems all the doom and gloom about it being inferior to the pro was a bit overstated, and the value increase more than makes up for it.

For performance reasons in a desktop case with a few drive bays spare I would always go for multiple SSDs over one large one, this allows you to set up a much more efficient system that takes advantage of the maximum bandwidth of your Sata 3 compliant motherboard.

My setup has two Samsung 840s set up with one as the OS/apps and the other for games and data.

...except the "bulk write" performance of these drives is slower than a spinny disk for the smaller capacity drives. Plus spinny disks will also allow you to take advantage of the aggregate bandwidth of multiple drives or parallel independent IO operations.

We still have single drives trying to keep up with systems with 6 or more CPUs. A bottleneck seems inevitable.

Crucial let me down in two ways. First, I've not had the problem with SSD's where you had to unplug them once a month in order for their internal software to reorganize.

You've not had the issue? So why bring it up?

Quote:

Secondly, their after warranty support IS NON-EXISTANT. If you have a problem with your drive after warranty wears out, they want NOTHING to do with you. They won't service it, repair it, exchange it for a fee.... TOTALLY THE WORST CUSTOMER CARE I'VE EVER HAD.

So, beware of Crucial. I've had much better performance and service with the other manufacturers.

Warranty last for a certain amount of time. Then it expires. So, Crucial are running their warranty exactly the same way as everyone else in the industry.

I don't know what your beef is with Crucial, but I and many other can categorically tell you, you're wrong.

I took out the Dell supplied Samsung PM830 128GB and fitted a 240GB Crucial M500. Performance is quite similar. One thing that does strike me is how much cooler the M500 runs compared to the PM830. The PM830 made the palmrest get uncomfortably hot after 4-5 hours, the M500 doesn't even warm the palmrest.

How does today's MLC technology stack up against yesterday's SLC? I have an intel X25-E 64GB SLC -- this type of SSD is real solid and I'll never have to worry about it (I use it in my laptop, not a server). But are new MLC SSDs ever going to attain the reliability of old SLCs?

Endurance has gone up on both, mostly due to controller tech and things like RAIN. Looking back, today's MLC is supposedly about as endurant as early SLCs, and today's SLC is even better.

That's massively incorrect. Not only is current tech SLC more "endurant" than current tech MLC, but it is also the case that older tech SLC Flash had a higher write endurance than current SLC Flash. That's because the new, smaller half-pitch processes result in NAND Flash that is inherently less reliable, be it SLC, MLC or TLC.

Manufacturers realized that even at 1000 rewrite cycle endurance, the SSD drives can be made to be "good enough". That's how Samsung's series 840 (TLC based) came to be. Yes, the write cycle endurance of those TLC Flash chips is abysmal compared to SSL, but with smart controllers and a level of acceptance from the consumers, it essentially doesn't matter.